1. Technical Field
The present invention relates to a projector.
2. Related Art
A projector which includes three light modulation devices for modulating three color lights in R (red), G (green), and B (blue) according to image information such as liquid crystal panels, and a cooling device for cooling the light modulation devices is known (for example, see JP-A-2001-281613).
The projector disclosed in JP-A-2001-281613 has the following cooling device for reducing the thickness of the projector.
The cooling device provided on the projector includes a sirocco fan disposed in the vicinity of the side of a projection lens, and a duct (channel) for guiding air discharged from the sirocco fan toward the respective light modulation devices.
The duct is a U-shaped component which surrounds three light entrance surfaces of a cross dichroic prism in the plan view, the prism is provided to combine the respective color lights modulated by the corresponding light modulation devices.
The air discharged from the sirocco fan and traveling within the duct sequentially passes through the light modulation devices from the sides of the light modulation devices in the order of the positions of the light modulation devices disposed adjacent to one another so as to cool the three light modulation devices.
According to the cooling device disclosed in JP-A-2001-281613, however, the bended structure of the duct and the small channel area of the duct narrowed by the light modulation devices contained within the duct increase the pressure loss within the duct. In this case, the static pressure within the duct rises, producing such a condition that a sufficient amount of air discharged from the sirocco fan is difficult to be securely supplied to the inside of the duct.
Particularly, since only a small amount of air is supplied to the light modulation device disposed in the most downstream part of the channel of the duct in the three light modulation devices, the temperature of the air supplied to this light modulation device rises. As a result, the temperature of the corresponding light modulation device is difficult to be decreased.
Accordingly, effective cooling for the three light modulation devices cannot be achieved.